Die and punch retainer device



NOV. 13, 195] R H N Y DIEAND PUNCH RETAINER DEVICE Filed Feb. 5, 1947INVENTOR.

Patented Nov. 13, 951

DIE AND PUNCH RETAINER DEVICE Richard Chaney, Dayton, Ohio, assignor toThe Sheflield Corporation, Dayton, Ohio, a corporation of OhioApplication February 3, 1947, Serial No. 726,113

14 Claims. (01. 279-76) This invention relates to retainer devices fordemountable punches, dies and the like.

One object of the invention is the provision of a holder or retainer ofthis character wherein the punch or die may be positively inserted andwithdrawn and,when inserted, will be held firmly and in a predetermineddefinite position.

Another object is the provision of a retainer having a screw engageablewith the shank of the punch or die to positively withdraw the shank, andan additional locking device which also normally acts to preventwithdrawal during operation.

Another object is the provision of a retainer device having a lockingroller which normally has line contact with the shank of the punch ordie and which acts to definitely locate the shank with respect to theretainer block, the roller being releasable from the shank by means of ascrew that is effective to positively withdraw the shank.

Another object is the provision in a retainer device of this characterof a punch or die having a shank provided with a cylindrical surfaceslidably engageable in the retainer block and having an annularlyrestricted portion that has straight ribs that may be engaged by a screwthread, a fiat gripping surface being provided between the end of theshank and the inclined ribs for engagement with a retaining roller.

Other objects and advantages of the invention will be apparent from thefollowing description, the appended claims and the accompanying drawing,in which Fig. 1 is a sectional view through the retainer centrallythrough the shank of the punch or die as indicated by the line 1-4 ofFig. 2;

Fig. 2 is a plan view of the retainer block as viewed on line 2-2 ofFig. 1 with the tool shank and its holding parts removed;

Fig. 3 is an end view of the tool shank;

Fig. 4 is a side elevation of the tool shank;

Fig. 5 is a sectional view through the retainer device centrally throughthe tool showing the position of the parts the instant withdrawalmovement begins; and v v Fig. 6 is a view of the retaining roller.

Referring more particularly to the drawing in which a preferredembodiment of the invention is shown, the punch or die H! has its shankll mounted with a sliding fit in a retainer block [2 which is connectedto the hard back plate l3 and mounted on die shoe I4 by means ofattaching screws l5 in the screw sockets l6. Dowel pins I1, arranged indowel openings l8, locate hergt mer ck. o the e s e- As shownin Figs. 1and, 2, the retainer block has a cylindrical tool socket 20 in which theshank ll fits. Intersecting or overlapping the circular tool socket is acavity 2! the lower portion of which is a, circular bore parallel to theaxis of the tool shank and intersecting the tool socket and forming aseat for an operating screw. 22, the lower side of the screw seat beingpartly closed by an apertured shoulder 23 through which the stem of awrench can be inserted to engage the recess 24 in the lower side of thescrew so that the screw can be turned in one direction or the other. i

The tool shank, at a suitable distance-from the upper end which engagesagainst the back plate l3 and in a zone which extends circum ferentiallymuch less than degrees, is provided with a series of ribs 25. The ribs,as shown,'are of V shape, either straight across the shank .or inclinedin accordance with the helical angle of the screw 22. As shown in Fig.3, 26- indicates the bottom of the rib grooves. These ribs may be veryreadily made by a grinding wheel of substantial diameter, provided withV-shaped ribs and moved back and forth in the directionrof the line 26.The tool shank may be inserted into the tool socket until the top rib 21engages the bottom thread on the screw 22 and thenwheri the screw isturned in the direction of the arrow shown in Fig. 5, the tool shankwill be drawn into the socket, the lower end of the screw remaining inengagement with the shoulder 23. Further rotation of the screw will thenbe prevented whenthe end of the screw shank engages theback plate I3. Itwill also be apparent that if the screw" is then rotated in the oppositedirection itrwilltend to screw itself upwardly along the ribs oftheshank but if the screw is held against upward travel its rotationwill positively withdraw thetool shank, thus facilitating the removal ofthe.

shank even if the shank should break above the bottom of the retainerblock.

The upper portion of the cavity 2| is elongated as shown in Fig. 2 andis inclined as shown in Fig. 1 to the axis of the tool socket, formingan inclined surface 29 having line contactwith a;

roller 30. The inclined portion of the cavity opens into the tool socketso that when the roller tool is so co-ordinated with the angle of thegripping surface 3| as to give a self-lockingor wedging engagementbetween the tool shank, the roller and the surface 29 when adownwardpull is exerted on the end of'the tooFits'elf. The tool willthus be firmly held with its end against the back plate l3 duringoperation by means of the roller, so that the holding action of thescrew 22 need not be relied upon to prevent loosening of the tool inoperation. The threads on the screw and the ribs on the tool with whichthe screw :threads engage will thus be relievedof the strain imposedduring operation. It has been found quite suitable to have the angle ofinclination-of the surface29 about 18 degrees with respect to the axisof the tool andhave the angle of -the-grippingsurface 3| about 14degrees to the axis -'of the tool although obviously variations may bemade in this angular relationship.

'When the roller is in firm engagement with bothithesurface-29 'and thegripping surface 3|, it will be apparent that rotational shifting of thetool is positively prevented. This is important where' the shaped thepunch or die isother than circular in order that the proper relationwill be:keptbetween thapunch andthe diein a cooperating die set.

.Theinclined flat gripping surface 3| extends far enough towards the endrib 21 so there is proper locking engagement between the rollerandtthetoolshank, and beyond the surface 3| betweentit' and theendrib 21the tool shank-may be'flattened as indicated at 35. Between thegrippingsurfacetl and the end of thetool shank isa'flatsurface 31 whichis somewhat closer to thetooleaxis than the base of the grooves =or ribs2-5'so1that the end of the tool shank when insertedrin the lower .end ofthe retainer block can be =moved.past.the threads on the screw 22without interference with those threads. When -theend-ofthe-shank isinserted and before the screw enga'ges the ribs .on the shank therolleris=engaged by the beveled surface 38 at the end of the-shank, or withthe end portion of the flat-surface 31 which is effective toautomatically position 'the tool-in an exact predetermined position orrelation in the retainer vand hold it against any rotationalmovementduring operation of the screw. Rotation of the'screw of courseinserts theshank until the roller rides down the inclinedzgrippingsurface 3| and until the end of the tool shank abuts against the platel3. In this (position the parts are as shown in Fig. 1, there being someclearance space between the bottom of-the roller'and the top of thescrew 22, and'there-being some space between the convolutions-of thespring 32. Both the screw and the roller have a holding actionpreventing withdra'walof the-tool'shank at this time.

I'dremove the tool shank, the screw is rotated in the opposite directionand since the roller still actsto hold the tool shank-the initialmoveretreats the roller, thus m'oving the rol1er up- 4 wardly to theposition shown in Fig. 5, from the normal locking position shown by thedash lines. The roller is thus moved clear of the inclined grippingsurface 35. The upward movement of the roller compresses theconvolutions of the spring which then forms a positive stop to preventfurther upward movement of the roller and thus prevent further upwardtravel of the screw. Continued rotation of the "screw is then fullyeifective to create a pulling force on the tool shank and retract theshank positively even though the tool may have been broken in operation.

Thewaction of the/roller in definitely positioning the tool 'sha-nk -andholding it against any rotational -movement-permits firm engagement oftheend of the tool-shank with the back plate l3 due to the yieldingaction of the roller in locating the tool shank. This avoids thenecessity of a positive key directly ibetween the tool shank andretainer. A.-.positive key between the tool shank and the retainer wouldnecessarily :have tobe made with extremeprecision in order to-fit firmlywithout .play in either the tool shank or. retainer and alsopermit forfirmengagement of the tool shank with the back. plate, and these areconditions that are impractical to obtain in -man--. ufacturingoperations.

As will be apparent, the parts are of simple form and construction andare capable of-operation over prolonged periods of time. The readyremoval of the punch or. die fromtheforward side of the retainer blockwithout having to remove the retainer block from the backplateorfrom theretainer shoe is of course adecided advantage in changing orreplacingthe punch or die.

While the form of apparatus herein described constitutes a preferredembodiment of the invention, it is to be understood that the inventionis not limited to this precise form of apparatus, and that changes maybemade therein without'departing from the scope of the invention whichis defined in the appended claims.

What is claimed is: t

1. A device of the character described,=compri s-. ing a retainer havinga tool socket for receiving the shank of a tool with "a sliding fit anda cavity at one side opening intothe socket, ascrew in said cavityprojecting radially into the -socket-to:en-. gage ribs on the toolshank-for insertingland withdrawing the tool when the screwis rotated.said retainer having an apertured shoulder for retaining one end of thescrew, and a-locking member in i said cavity adapted for locking'engagement with a side- 0f the sh'a'nk to hold th'e shank againstremovaL: said screw when rotated to withdraw-the shankoperating torel'easesaid locking member.

2. A device of the character idescribed, comprising aretainer havingatool socket-forreceivingtheshank of -a-tool with a slidin'gfit and acavity at one side opening into --the socket, a screw in said cavityprojecting radially'intothe socket to engageribson the tool shankforinserting and withdrawing the tool-when-the-screwis rotated, -saidretainer having an apertured shoulder for retaining oneend of thescrewfiand a locking roll in said cavity adapted for locking engagementwith-a sideof the shan-k tohold-the shank against-removal, said screwwhen-rotated to withdrawthe shank being movable along-the ribs of theshank to release saidlocking roll.

-3. A device of the characterdescribed/comprising a retainer having a-"tool *socket for" receiving the shank of a tool with a sliding flt andacavity said retainer having a portion for retaining one end of thescrew, and a spring pressed holding member in said cavity engageablewith a side of the shank to position the shank against rotation,

socket for receiving the shank of a tool with a said screw having aportion for releasing the holding member when the screw is operated towithdraw the tool.

4. A device 'of the character described, comprising aretainer having atool socket for receiv ing the shank of a tool with a sliding fit and acavity at one side opening into the socket, a screw in said cavityparallel to the socket and projecting into the socket to engage ribs onthe tool shank for inserting and withdrawing the tool when the screw isrotated, said retainer having an apertured shoulder for retaining oneend of the screw, said cavity having a surface inclined from the back ofthe retainer toward the socket, a positioning member in said cavityengagable with a side of the shank and said inclined surface, and springmeans urging said member towards the socket, said member and screwhaving a spaced relation when the shank is positioned so that rotationof the screw to withdraw the shank first releases the member from theshank.

5. A device of the character described, comprising a retainer having atool socket for receiving the shank of a tool with a sliding fit and acavity at one side opening into the socket, a screw in said cavityprojecting radially into the socket to engage ribs on the tool shank forinserting and withdrawing the tool when the screw is rotated, saidretainer having an apertured shoulder for retaining one end of thescrew, and a locking roll having an axis extending transversely of theaxis of the socket and arranged in said cavity so that its cylindricallocking surface is adapted for line contact and wedging engagement witha side of the shank to hold the shank against removal, said screw whenrotated to withdraw the shank being movable along the ribs on the shankto release said locking roll from the shank.

6. A device of the character described, comprising a retainer having atool socket for receiving the shank of a tool with a sliding fit and acavity at one side opening into the socket, a screw in said cavityparallel to the socket and projecting into the socket to engage ribs onthe tool shank for inserting and withdrawing the tool when the screw isrotated, said retainer having an apertured shoulder for retaining oneend of the screw, a roll in said cavity extending transversely of thesocket and adapted for line contact with a side of the shank to hold theshank in position, spring means urging the roll against the shank, saidscrew when rotated to withdraw the shank operating to release said roll.

'7. A device of the character described, comprising a retainer blockhaving a cylindrical tool receiving bore and a cavity providing a guidesurface inclined relatively to said bore, a roller in said cavity havingits axis transverse of said bore and operable along said surface withline contact therewith and projecting into said bore, spring meansurging said roller towards said bore, and a screw for positivelyinserting and withdrawing the tool and engageable with the roller toretract it from the bore.

8. In a retainer device for demountable punch, die or like tool aretainer block having a tool sliding fit, a toolhaving ashank insaidsocket. formed withan annularly'restricted series of ribs,andfhaving a fiat gripping surface between the ribs andthe end of the shank,said retainer block having ,a cavity at one side of the tool socke'tandextending to the tool socket, means for'securing the retainer to abacking plate, a screw, in said cavity projecting radially into thesockt and engaging the ribs on the tool shank for inserting andwithdrawing the tool shank whentheyscrew is rotated, said block havingan apertured shoulder for retaining one'end of the screwand providingaccess to the screw, a lockingrollerin said cavity having line contactwith thee ggripping surface on the shank to prevent rotational andwithdrawing "movement of the shank;,spring means urging said rolleragainst said gripping surfaces, said screw when rotated to withdraw theshank operating to release the locking roller.

9. A tool adapted for detachable mounting in a retainer, said toolhaving a shank portion which throughout the major portion thereof is aplain cylindrical surface adapted for sliding movement, said cylindricalsurface having an annularly restricted portion provided with ribsadapted for engagement with a screw thread to effect a longitudinalsliding movement of the tool shank, the shank of the tool having a flatgripping surface between the end of the shank and said ribs.

10. A tool adapted for detachable mounting in a retainer, said toolhaving a shank portion which throughout the major portion thereof is aplain cylindrical surface adapted for sliding movement, said cylindricalsurface having an annularly restricted portion provided with inclinedstraight ribs adapted for engagement with a screw thread to effect alongitudinal sliding movement of the tool shank, the shank of the toolhaving a fiat gripping surface extendingfrom the end of the shank tosaid inclined ribs.

11. A tool adapted for detachable mounting in a retainer, comprising ashank portion which throughout the major portion thereof is a plaincylindrical surface adapted for sliding movement, said cylindricalsurface having an annularly restricted portion provided with ribsadapted for engagement with a screw thread to efiect a longitudinalsliding movement of the tool shank, the shank of the tool in the zonebetween the end of the shank and said ribs having a gripping surface ofsuch character that transverse sections through the shank where suchgripping surface is located indicate the gripping surface as a straightchordal line extending entirely across the Shank.

12. A tool adapted for detachable mounting in a retainer, comprising ashank portion which throughout the major portion thereof is a plaincylindrical surface adapted for sliding movement, said cylindricalsurface having an annularly restricted portion provided with ribsadapted for engagement with a .screw thread to effect a longitudinalsliding movement of the tool shank, the shank of the tool having a, flatgripping surface between the end of the shank and said ribs with saidgripping surface extending at an angle to the axis of the shank so thatthe surface lies a progessive distance from the shank axisas itapproaches the end of the shank.

13. A device of the character described comprising a retainer having atool socket for receiving the shank of the tool with a sliding fitandacavjitSrat ne si e 5m he. fth s k n. mean operable frem th exterieotffthe lsgcke't; fdr bsitively-moving the "tool 5h axiauy; in-t-liwafdly fir butwelr ly and jadd n One, $65 15 in"; said socket in generalaxial alignment with S9; first ineans for retaining the shank again toutH The ow g ieferences are of record in the 'file of this patent: p

r. 317.: TUNITED ATES PATENTS v wardmovement. H Number "Name Dat N a M.A device Of the character "described '99 Re.1 9, 1'1'1" Hai'rington Mar,13-,, 1934 prising a retainer having a tool kooke'tf'fei 1,974,217Richard Sept 18 19 35;; ceiving' the'shank of a teol with a sliding 72,137,557 Ziganek Nov.-, 22, 1938 said retainer having a cavity 'atqzieside'objen 2,152,072 Mantej, 1 V Iar,-;28,.- 19 3 9; inginto thesocket, theaded meansffor poeitiirei 2,385,652 Borg LQ. Oct. 9, 1945moving the shank of the tool into andeuflof 2,393,986 Gullberg Feb. 5,1946 the socket'and alocking member eodperatffiely"" associated'withsaid threaded. means fol-holding u the tool in th socket RICHARD CHANEY.

